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GCN Circular 17674

GRB 150403A: Fermi GBM Detection
2015-04-04T14:04:39Z (9 years ago)
Binbin Zhang at UAH <>
Bin-Bin Zhang (UAH) reports on behalf of the Fermi GBM Team:

"At 21:54:10.95 UT on 03 April 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150403A (trigger 449790853 / 150403913),
which was also detected by the Swift (Lien et al. 2015, GCN 17665)
and Fermi LAT (Longo et al. 2015, GCN 17667). The GBM on-ground
location is consistent with the Swift position. The trigger resulted
in an Autonomous Repoint Request (ARR) that was accepted and the
spacecraft slewed to the GBM in-flight location. The initial angle
from the Fermi LAT boresight is about 55 degrees.

The GBM light curve shows a bright single pulse with a duration (T90)
of about 22.3 s (50-300 keV). The time-averaged spectrum from
T0+3.3 s to T0+25.6 s is best fit by a Band function with
Epeak = 311 +/- 14 keV, alpha = -0.72 +/- 0.02, and beta = -1.85 +/- 0.03.

The event fluence (10-1000 keV) in this time interval is
(5.73 +/- 0.05)E-05 erg/cm^2. The 1.024-sec peak photon flux
measured starting from T0+11.1 s in the 10-1000 keV band
is 33.5 +/- 0.5 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

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